1.Characteristics of left atrial function real-time three plane strain rate imaging in patients with hypertension and coronary artery stenosis and their significances
Ye ZHOU ; Yunzhang CHENG ; Jingyuan HUANG
Journal of Jilin University(Medicine Edition) 2016;42(5):1019-1023
Objective:To investigate the characteristics of real-time three plane strain rate imaging of left atrial function in the patients with primary hypertension and coronary artery stenosis, and to evaluate its clinical application value.Methods:Total 82 patients with primary hypertension were selected and divided into primary hypertension group (EH group,n=42)and primary hypertension complicated with coronary artery stenosis group (EHCHD group,n=40).In addition,the physical examination people were selected as control group (n=42).All the subjects were examined by conventional echocardiography,and the left atrial function in real-time three plane strain rate imaging was analyzed.The parameters of conventional echocardiography and real-time three plane strain rate imaging were compared.Results:Compared with control group,the systolic left atrial mean peak strain rate (SRs),early diastolic left atrial mean peak strain rate (SRe)and SRe/SRa of the patients in EH group and EHCHD group were significantly decreased (P < 0.05);the atrial systolic mean peak strain rate (SRa)and Time-SRa in EH group and EHCHD group were significantly increased (P <0.05).Compared with EH group,SRs,SRe and SRe/SRa in EHCHD group were obviously decreased (P < 0.05 );SRa and Time-SRa were significantly increased (P <0.05).Conclusion:Real-time three plane strain rate imaging can easily and accurately analyze the left atrial function in the patients with essential hypertension and coronary artery stenosis,it is worth to popularize in clinical application.
2.Application of Link Mechanism in Otolaryngology Chair
Chinese Journal of Medical Instrumentation 2013;(5):343-344,347
Design otolaryngology chair’s up-down assemble by applying link mechanism. And analysing the speed and accelerate of mechanism in CATIA’s motion mechanism module to verify its actural running status. Draw the effective design, make the successful prototype.
3.Numerical simulation of the internal noise in the pressure generator of a continuous positive airway pressure ventilator.
Yunzhang CHENG ; Fangfang HUANG ; Lihua ZHU
Journal of Biomedical Engineering 2013;30(2):312-315
It is important to overcome the problem of noise for the research and development of ventilator technologies. Previous research of this subject showed that the pressure generator, produced by German EMB-PAPST Company and specially used for continuous positive airway pressure (CPAP) ventilator, created noise easily, due to local backflow in the volute, uneven velocity distribution in the impeller and local negative pressure in the inlet of the impeller. Based on the previous research, a combination of the computational fluid dynamics (CFD) software FLUENT and steady-state solution of noise source of Reynolds-Averaged Navier-Stokes (RANS) was used in this study. We combined equation of Lilley and Synthetic Turbulence to get the information about speed fluctuation of the pressure generator, which is used to finish noise prediction. After detailed analysis, it showed that noise source of different degrees spreaded around the inlet of the impeller and the volute, interface of blade edge and corner of the volute tongue, which influenced its overall performance to certain extent. Therefore, its structural design needs to be improved.
Algorithms
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Computer Simulation
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Continuous Positive Airway Pressure
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adverse effects
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instrumentation
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Equipment Design
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methods
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Models, Theoretical
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Noise
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prevention & control
4.The numerical simulation of the internal flow field inside the pressure generator of a continuous positive airway pressure ventilator.
Yunzhang CHENG ; Lihua ZHU ; Weiguo ZHANG ; Wenquan WU
Journal of Biomedical Engineering 2011;28(6):1131-1135
The problem of noise in ventilator has always been an important topic to study in the development of the ventilator. A great number of data are showing that there are still large gaps of research and application levels in noise control of the ventilator between China and some more advanced foreign countries. In this study, with cooperation of the Shanghai Medical Equipment Limited Liability Company, we used the computational fluid dynamics (CFD), software FLUENT, adopted the standard k-epsilon turbulence model and the SIMPLE algorithm to simulate the inner flow field of the continuous positive airway pressure (CPAP) ventilator's pressure generator. After a detailed analysis, we figured out that there are several deficiencies in this ventilator, like local reflow in volute, uneven velocity distribution and local negative pressure in inlet of the impeller, which easily lead to noise and affect the ventilator's performances. So, it needs to be improved to a certain extent.
Algorithms
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Computer Simulation
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Continuous Positive Airway Pressure
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adverse effects
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instrumentation
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Equipment Design
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methods
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Models, Theoretical
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Noise
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prevention & control
5.Research on flow characteristics in a non-blade centrifugal blood pump based on CFD technology.
Yunzhang CHENG ; Binhai LUO ; Wenquan WU ; Lei JIANG
Journal of Biomedical Engineering 2010;27(5):1133-1137
The problem of thrombus and hemolysis in blood pump has always been an important topic to study in the development of the blood pump. Numbers of research results show that it is the complicated flow and the high shear stress of the mechanical movement that result in the thrombus and hemolysis. In this study, with the cooperation of Shanghai Children's Medical Center, we have used computational fluid dynamics (CFD) commercial software FLUENT to compute and analyze the flow characteristics in a non-blade centrifugal blood pump. The results figure out that this pump has a reasonable flow distribution and the shear stress distribution is under the critical broken state of red blood cell; meanwhile, there is less thrombus and hemolysis in this pump. So it is in the foreground for clinical use.
Computer Simulation
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Heart Defects, Congenital
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therapy
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Heart-Assist Devices
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adverse effects
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Hemodynamics
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Hemolysis
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Hemorheology
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Humans
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Models, Theoretical
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Stress, Mechanical
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Thrombosis
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prevention & control
6.Application of link mechanism in otolaryngology chair.
Chinese Journal of Medical Instrumentation 2013;37(5):343-347
Design otolaryngology chair's up-down assemble by applying link mechanism. And analysing the speed and accelerate of mechanism in CATIA's motion mechanism module to verify its actual running status. Draw the effective design, make the successful prototype.
Equipment Design
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Otolaryngology
;
instrumentation
7.Detection and Rectification of Radiation Emission from Medical Laser Equipment.
Chinese Journal of Medical Instrumentation 2019;43(5):372-374
By introducing the unqualified cases of radiation emission test of medical laser equipment, this paper analyses the causes of the problems and the corrective measures adopted, and analyses the effectiveness of the corrective measures. It is proposed that the design rules and rules related to radiation emission should be mastered from the input stage of product design and development, and the radiation emission problem should be considered and solved as soon as possible.
Equipment Design
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Laser Therapy
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instrumentation
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Lasers
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Light
8.Research progress in deep learning-based digital mammography for accurate diagnosis of breast clustered microcalcification
Xuan YANG ; Aiping DONG ; Yunzhang CHENG ; Baosan HAN
International Journal of Biomedical Engineering 2024;47(5):497-503
Breast clustered microcalcification (BCM) is one of the most critical X-ray signs of early breast cancer. However, due to the fact that BCM is very tiny and hidden, and manual interpretation is susceptible to subjective factors such as visual fatigue, manual diagnosis of dense BCM based on X-images suffers from a low detection rate, high false-negative rate, and high recall rate. In recent years, with the continuous optimization innovation of deep learning algorithms, and advancements of computer hardware technology, new hope has been brought to accurate diagnosis of BCM, which is expected to realize the accurate assessment of individual breast cancer risk. In this review, the research progress of deep learning for accurate diagnosis of BCM was summarized, such as full-field digital mammography (FFDM), digital breast tomosynthesis (DBT) and contrast-enhanced mammography (CEM), as well as the future developments in this field were discussed.
9.Current status and progress of artificial intelligence in endoscopic and imaging diagnosis of colorectal cancer
Xian ZHANG ; Qingguo WANG ; Yunzhang CHENG ; Chen HUANG
Chinese Journal of Digestive Surgery 2024;23(4):622-628
Colorectal cancer is a common malignant tumor of the digestive system globally, with both its incidence and mortality rates increasing annually in China. In recent years, there has been exponential growth in technology based on artificial intelligence, leading to significant advancements in the field of medical imaging diagnosis. Particularly in the application of colonoscopy, CT and magnetic resonance imaging (MRI), artificial intelligence, leveraging its advanced image recognition and feature analysis capabilities, has provided new perspectives for the diagnosis of colorectal cancer, thereby driving the realization of precision medicine. Currently, various artificial intelligence algorithms are either under development or optimization, such as performance comparisons of various artificial intelligence-assisted systems, the collaborative application of multiple algorithms, and integration with other omics. Additionally, challenges persist in the integration difficulty, interpre-tability and credibility, as well as cost and resource limitations of AI in clinical practice, necessitating further standardization and improvement. The authors explore the current status and progress of artificial intelligence in endoscopic and imaging diagnosis of colorectal cancer from four aspects: colonoscopy, CT, MRI and other imaging examination for reference and reference by peers.
10.Influence of Fixation Methods on Fixation Effects of Femoral Neck Fracture
Wenqing WEI ; Haipo CUI ; Jian CHEN ; Yunzhang CHENG ; Qianli CHENG
Journal of Medical Biomechanics 2020;35(2):E216-E222
Objective To study the influence of hollow screws with five kinds of spatial distributions on the fixation effect of femoral neck fracture. Methods Geometric models of femoral neck fracture with Pauwels type I, II and III were built by reverse engineering according to CT images of the femur. Based on the finite element analysis software ANSYS, the stress distributions of internal fixation, head side and stem side of femoral neck and the displacement distributions of the model fixed by different methods were obtained. Results For femoral neck fracture with Pauwels type I, II and III, the maximum stresses at head side of femoral neck were the inverted triangle fixation method, two-screw parallel fixation method, two-screw parallel fixation method, respectively. The maximum stresses at stem side of femoral neck were the inverted triangle fixation method, inverted triangle fixation method and two-screw parallel fixation method, respectively. The minimum stresses on the screws were the cross fixation method, and the minimum displacements of the model were double-supported fixation method. Conclusions The probability of screw deformation and fracture is the smallest for cross fixation method. Inverted triangle fixation method can provide a good mechanical environment for fracture site. For femoral neck fracture with Pauwels typeⅠ and Ⅲ, double-supported fixation method has the strongest ability to prevent femoral neck shortening. While for femoral neck fracture with Pauwels typeⅡ, cross fixation method has the strongest ability to prevent femoral neck shortening.